try {
  TransformerFactory xformFactory = TransformerFactory.newInstance();
  Source xsl = new StreamSource("stylesheet.xsl");
  Transformer stylesheet = xformFactory.newTransformer(xsl);
  Source request  = new StreamSource(in);
  Result response = new StreamResult(out);
  stylesheet.transform(request, response);
}
catch (TransformerException e) {
  System.err.println(e); 
}